Public vs. Private Blockchain: Comparison

Blockchain is the distributed ledger of all crypto transactions. Blockchain can be both private and public. Let’s investigate what it means and how these two types differ.

What is the public blockchain?

Public (permissionless) blockchain is open to everybody without restrictions. Everyone has the access to it, is able to check the whole transfers history and even create smart contracts. Joining and participating in public distributed ledger is easy and is not restricted.

Advantages:

• All information can be checked and verified as everybody can look at it.
• No frauds or corruption are possible – all information stays on the ledger.
• The more users verify transfers, the more security chain gets.
• The network encourages users to participate.

Disadvatages:

• Little or no privacy for transactions – remember, everyone can see everything.
• Transactions take comparatively long time and a lot of energy to get processed.

Examples:

Bitcoin is the public protocol which can be downloaded and used by everyone. Ethereum is another public one which allows users to create their own smart contracts without building their own ecosystem. It also allows to develop Dapps.

What is the private blockchain?

Private (permissioned) blockchain establishes restrictions on who has a right to be a participant of the network and take part in certain transactions.

To join a permissioned ledger, a user needs an invitation, which will be approved or disapproved by the network starter or moderator. The access can also be approved by other already participating users. Control mechanism differs according to the established set of rules.

As for accessing money operations on private ledger, only money transfer participants will be able to access it.

Advantages:

• Personal choice of the consensus protocols.
• Fast speed of money operations.
• This ledger is efficient regarding scalability.
• It more easily and more efficiently complies with regulatory requirements.
• Companies can ensure internal security by utilizing the private ledger.

Disadvatages:

• There is a lack of trust.
• Centralized organization – rules are set up by the authority.
• Corruption and any manipulations stay undetected.
• Data can be changed and users without permission are not able to check it.
• More vulnerable to attacks by network’s participants.

Examples:

Hyperledger Fabric of the Linux Foundation is a private ledger designed to meet the enterprise requirements. Ripple is a private blockchain as well – it determines who can validate money transfers on the network. For instance, it included Microsoft and MIT as ones of those who act as transactions validators.

How are they similar?

Both public and private ledgers share some elements and traits.

• They are decentralized P2P networks.
• They have replicas synchronized through a consensus protocol.
• They ensure ledger’s immutability.

Private ledger may be a good solution for companies and enterprises as not all the confidential information will be revealed to the public. Also, companies can save money and time running a private network. Public blockchain, however, is a DLT which has already made work processes more efficient in many industries due to the open access to data. It is a right choice for establishing the high-level trust between all participants and minimizing the fraud level.